Google Messages adding support for dual SIM RCS [U]

Since launch, Google Messages has not allowed RCS on more than one phone number, but the app is now adding support for dual (multi) SIM.

Update 8/17: Back in January, there were some reports of dual SIM RCS support in Google Messages, but it was eventually pulled. The capability looks to be rolling back out again, with one new report from a Messages beta user on the Nothing Phone 2.

We see two SIM cards “Connected” in RCS setting, while there’s a new “Backup format for sending attachments” setting that says “SMS with a link.” This sounds like the Google Photos video upload feature that was quietly removed last year. A return would be unexpected.

Original 1/4: Version 20240102_00_RC01, which is the first beta of the new year, features various strings related to multi_sim RCS support.

• Send and receive RCS chats on SIM %1$d when you verify your number
• SIM %1$s RCS Toggle
• Your IT administrator turned off RCS chats for all SIMs. %1$s
• RCS chats for all numbers will be turned offf
• RCS chats for both numbers will be turned off

From the beginning, Google has said “RCS chats are available for your default or preferred call SIM at this time and may be available for other SIMs later.”

It looks like the company is now getting around to adding support, which is important for RCS adoption internationally. Those with dual SIM phones are seeing multiple numbers appear in Settings > RCS chats, which picked up some visual tweaks in recent weeks. Note the checkboxes next to each number instead of the generic SIM card icon.

From the report we have today, the second number cannot be set up right now, with Google not yet enabling the server-side elements for dual/multi SIM RCS support in Messages. 

Update 1/5: Users are now seeing dual SIM RCS support go live. You get to choose which number you want to use for an RCS conversation.

Credit: u/aniruddhdodiya

More on Google Messages:

Thanks to JEB Decompiler, from which some APK Insight teardowns benefit.